Propellent cartridge



Dec. 22, 1964 o. N. LEWIS ETAL PROPELLENT CARTRIDGE Filed July 25, 1961 FIG-3 OLIVER NELSON LEWIS CHARLES J. DE CARO BY ATTORNEY United States Patent Ofifice 3,162,125 Patented Dec. 22, 1964 3,162,125 PROPELLENT CARTRIDGE Oliver Nelson Lewis, Woodbridge, and Charles J. De Caro, Orange, Conn, assignors to Olin Mathieson Chemical Corporation, a corporation of Virginia Filed July 25, 1961, Ser. No. 126,629 6 Claims. (Cl. 10243) This invention relates generally to explosive propellent cartridges and is particularly useful in powder actuated tools.

Such tools powered by a charge of explosive have been found advantageous in the driving of fasteners, for example, and the propellant is usually contained in a conventional rim-fire type of cartridge modified so as to hold the higher charge of powder needed for the purpose as compared to the powder charge of ammunition. A standard caliber of cartridge has been used, but does not lend itself well to use in these tools where the diameter of the fasteners are larger than the outside diameter of the cartridge case. In such instance, the fasteners and the cartridges can not be breech loaded into a conventional chamber of the tool barrel unless a sub-calibre chamber is provided or unless a removable breech plug be inserted as an adapter. While this solution has certain advantages, the removable breech plug sulfers from the disadvantage of handling of an additional part which can prove awkward and which may even interfere with tool operation, particularly where the breech plug is dropped and lost. Especially in the slide action type of tool, the use of the conventional type of cartridge case with the high powder loads used sutfers from disadvantages in the way such cases have to be inserted and ignited and then ejected by a still further separate part. Furthermore, where the cartridge chamber is of such divided construction, handling of the cartridge can be awkward, the ejector when kept small can tear away the cartridge rim, and there is always the risk of the cartridge case bursting from the pressure of explosion in the region of the joint, especially when thin walled small-calibre rim-fire cartridges are used.

To overcome these difliculties, one approach proposed has been the use of various forms of cartridge cases adapted to be inserted rearwardly into the breech structure of the tool instead of forwardly into the breech of the tool barrel. However, this also has attendant disadvantages from difiiculty of properly igniting and thereafter extracting such special cartridges which are rather costly in manufacture as are cartridges of large calibre.

One of the objects in this invention, therefore, is to provide a propellant cartridge having the least deviation from standard manufacturing procedures for cases for tools of this type. Another object is to provide a propellant cartridge preferably of small caliber of novel construction as well as economic construction. Another object is to provide an economic cartridge of the rim-fire cartridge to be loaded head first. Still another object is to provide such a cartridge especially adapted for a compact arrangement of the firing pin and/ or the ejector. Other objects and advantages will become apparent from a description of several embodiments and from the accompanying illustration thereof shown in the drawing in which:

FIG. 1 is a side perspective view partly in cross section of one embodiment;

FIG. 2 is a cross sectional view of another embodiment shown mounted in the chamber portion of a suitable explosive operated device shown with the barrel and breech block portion thereof;

FIG. 3 is a side view partly in cross section of still another embodiment in the environment of another typical and suitable device; and

FIG. 4 shows a still further embodiment partly in longitudinal section.

In accordance with this invention there is provided a rimless cartridge of the rim-fire type characterized by substantial uniformity of the diameter of the circumferential periphery of the head and the outside diameter of the body adjacent the rim-fire head. Such a cartridge is provided by assembling a standard rim-fire case and a jacket of paper, plastic, or other suitable material of sufficiently elastic character. At least one end of the jacket has outside a diameter coextensive with the circurnferential periphery of the rim-fire type of head. The jacket may take the form of a tube which may he slid over a conventional rim-fire type of case or it may be provided by molding of the jacket about the case. When the jacket is of paper, it is preferred that it be of spirally wound structure so as to avoid a longitudinal seam. A suitable plurality of layers of such a spiral winding are employed. In any event, the inside and the outside diameter of the jacket are smooth for proper support of the cartridge in the chamber; the outside diameter of the jacket, however, may be modified, particularly when the jacket material is so tough as to ofier substantial rigidity, by a reduction or bevel adjacent a front-faced surface of the rim-fire head to provide a continuous circumferential groove thereat for the reception of the tip of the firing pin. This assembly is made as an expendable composite all of which can be thrown away after use and ejection.

In the simplest construction the jacket is a sleeve of uniform outside diameter along its length, but it is also contemplated that the end of the jacket opposite the head have a diameter larger than the diameter of the rim-fire head. According to this embodiment, the outside diameter adjacent the head is substantially that of the head while the outside diameter at the opposite end is sufliciently larger thereby providing a tapered jacket having its maximum diameter at its cross section situated at the mouth of the case and its smallest diameter situated in the cross section next to the head. This adapts the cartridge to a complementary flared contour situated, for example, in the forwardly open recess in the breech block for the purpose of more firmly seating the cartridge in the breech block by compressive action when the barrel is closed on the block, particularly where the jacket material is resilient. A jacket of such tapered construction is also adapted for better retention and sealing and for easier ejection. With the proper selection of a suitable jacket material and taper, the jacket may provide a degree of self-ejection. For example, with a jacket material of polyethylene or of an equivalent self lubricating olefinic polymer and with a self-releasing taper the resultant cartridge will tend to pop out of the breech block when the barrel is withdrawn therefrom. The jacket may take the form of a deep cup the closed end of which is situated at the mouth of the case and obviates the need for a separate closure Wad.

The jacket may be colored for visual identification of the various loads employed in the case.

In FIGURE 1, the composite cartridge 1 consists of a brass case having a rim-fire head 2 containing the ring of priming mixture 3 and a charge of suitable propellant 18. It has recessed Within the mouth a Wad 8 forming a closure for the contents of the case opposite the closed base 6. The jacket 5 in the form of a sleeve is either frictionally or adhesively assembled on case 4 and extends from the end at the mouth to the rim-fire head in abutment with the jacket. The outside diameter of jacket 5 is substantially that of the outside diameter or periphery of primer rim 2.

The composite cartridge 10 of FIGURE 2 likewise includes case 4 having a rim-fire head 2 adjacent the base 6. The cartridge is charged with explosive powder 18 closed in the case by end wad 8 disposed at the mouth. Spirally wound about the case are two or more layers of paper forming the jacket having a uniform outside diameter substantially equal to that of head 2. One end of the jacket is beveled or otherwise fore-shortened at 16 to form a tapered recess around the cartridge. The other end of the jacket may be extended at 17 particularly when the bore 41 in barrel 40 is of a calibre not in excess of the outside diameter of the jacket the extended end of which in this arrangement helps form a better seal between barrel 40 and breech structure 20. Jacket 15 is free from a weakening longitudinal or crosswise seam because it is preferably an integral tube comprising layers of helically wound tape with the joints of separate layers in staggered relationship in the lays secured together.

From FIGURE 2 it is apparent that this invention provides a cartridge which can be loaded rearwardly or oppositely into the block as compared to the conventional manner of loading cartridge cases into the barrel of a gun. This reverse manner of loading makes it possible to insert the cartridge rim first into its chamber while the mouth of the cartridge faces the bore of the barrel. This obviates the need for providing a chamber in the bore of the barrel for each size of the cartridge used and for each calibre of fastener and barrel bore needed. The cartridge is of one size preferably of .22 calibre and is adapted for use with any calibre of barrel bore such as that indicated at 41 which may be considerably less than that of the case, or at 42 which may be in excess of the diameter of the entire cartridge.

One of the tapered cartridges also contemplated as a preferred embodiment is shown in FIGURE 3 as 101 and comprises case 4 and jacket 25 the small end 26 of which is next to rim-fire head 2 in coextensive peripheral relationship. The large end 27 of the tapered jacket 25 is substantially coextensive with the mouth of the case but may extend beyond it as shown in FIGURE 2. This type of cartridge may be used either in the device illustrated in FIGURE 2 or that of FIGURE 3.

This invention is adapted for use with the flat faced ejector pin 13 forming the bottom of the chamber in structure of FIGURE 2.

The cartridge of FIGURE 2 is fired by the pin 21 movably mounted in transverse bore 22 of breech block structure 29.

The tool shown schematically in FIGURE 3 for use with cartridge 101 has a barrel 50, a piston member 60 and a striker or blocking member 70, the latter two of which are received in the bore 51 of the barrel. Member 60 has a driving projection 61 for impacting a fastener. Member 70 has a cartridge recess 71 with a tapered sidewall 72 either complementary to the taper of the cartridge 101 or of lesser inclination. At the base of the recess there may be provided a firing point tip or projection 73 for acting on the rim-fire head 2 when the members 60 and 70 are driven together sufiiciently with cartridge 101 in between. It will be understood that member 70 may alternately be the striker whereupon member 60 becomes the piston, both being modified accordingly. The striker is adapted for manual driving in bore 51 by a hand hammer blow on the projecting end of the striker. Although tip 73 is shown, a conventional longitudinally acting firing pin may be used, or the side-acting one of FIGURE 2.

It will also be understood by those skilled in the art that various other changes may be made in the foregoing embodiments. For example, the recess in block 20 may be tapered to receive a cartridge of the type shown in FIGURE 3. The jacket may be cup-shaped instead of open-ended and such a jacket 35 is shown in FIGURE 4 assembled on case 4 with one end against rim-fire head 2 and the other closed at 36 to close the case without need for a separate wad.

Such changes may be made without departing from the spirit and scope of the invention as set forth in the appended claims. The jacket preferably includes a lubricant such as M03 graphite, wax, oil, or a grease which may be incorporated, for example, by impregnation in the paper of FIGURE 2.

No matter how the tool is modified, the cartridge according to this invention is fed into the tool cartridge chamber or recess rim-fire head first and is adapted for firing by any one of various means including a transverse or inclined pin acting on the front-faced side of the rim-fire head 2 for pinching the primer material 3 therein back against the base 6 as the latter is in abutment with the bottom of the cartridge recess.

What is claimed is:

1. An explosive propellant cartridge including a case having an annular rim and an integral tubular body and said rim extending radially outwardly from said tubular body at one end, primer means inserted in the rim of said cartridge, said rim having a front-faced surface, a non-metallic jacket completely encircling said tubular body and extending between said front-faced surface of said rim and at least the other end of said body, said jacket having an outside diameter adjacent said rim which is not more than the outside diameter of said rim to expose said rim sufficiently for firing by a generally transversely disposed firing pin operable on said surface.

2. The cartridge of claim 1 wherein the jacket is tapered to a maximum outside diameter at the other end.

3. The cartridge of claim 1 wherein the end of the jacket extends axially beyond the other end.

4. The cartridge of claim 3 wherein the jacket is cupshaped and its extended end is closed over the other end of the tubular body.

5. The cartridge of claim 1 wherein at least the periphery of the end of the jacket adjacent the rim is spaced forwardly from the front-faced surface to form an annular groove between said rim and jacket.

6. The cartridge of claim 5 wherein the jacket end adjacent the rim is beveled so that the groove is of tapered configuration.

References Cited by the Examiner UNITED STATES PATENTS 1,340,245 5/20 Peck 102-43 2,894,456 7/59 Olin 102-43 2,931,039 4/60 Henning et al. 102-43 X 2,984,182 5/61 Fienup et a1 102-42 2,984,836 5/61 SChenkel 102-38 X 3,026,801 3/62 Oberfell 102-42 3,034,433 5/62 Gronn 102-43 3,048,849 8/62 De Caro et al. 102-43 3,078,800 2/63 Bumiller 102-38 FOREIGN PATENTS 604,113 8/ 60 Canada.

SAMUEL FEINBERG, Primary Examiner.

ARTHUR M. HORTON, Examiner. 

1. AN EXPLOSIVE PROPELLANT CARTRIDGE INCLUDING A CASE HAVING AN ANNULAR RIM AND AN INTEGRAL TUBULAR BODY AND SAID RIM EXTENDING RADIALLY OUTWARDLY FROM SAID TUBULAR BODY AT ONE END, PRIMER MEANS INSERTED IN THE RIM OF SAID CARTRIDGE, SAID RIM HAVING A FRONT-FACED SURFACE, A NON-METALLIC JACKET COMPLETELY ENCIRCLING SAID TUBULAR BODY AND EXTENDING BETWEEN SAID FRONT-FACE SURFACE OF SAID RIM AND AT LEAST THE OTHER END OF SAID BODY, SAID JACKET HAVING AN OUTSIDE DIAMETER ADJACENT SAID RIM WHICH IS NOT MORE THAN THE OUTSIDE DIAMETER OF SAID RIM TO EXPOSE SAID RIM SUFFICIENTLY FOR FIRING BY A GENERALLY TRANSVERSELY DISPOSED FIRING PIN OPERABLE ON SAID SURFACE. 